Adjustable perforating punch assembly



1957 s. c. PELLEGRINO ADJUSTABLE PERFORATING PUNCH ASSEMBLY Filed March 9, 1956 SAMUEL I INVENTOR. c'. PEALEGfl/VO United States Patent 2,808,108 ADJUSTABLE PERFORATHNG PUNCH ASSEMBLY Samuel C. Pellegrino, Buffalo, N. Y.

Application March 9, 1956, Serial No. 570,599

3 Claims. (Cl. 164-124) This invention relates generally to machine tools and is more particularly concerned with a novel piercing punch assembly.

As presently advised, piercing punches generally include an elongated integral member made from a single piece of high test machine tool including an elongated body portion and a reduced diameter shank portion, the juncture between the body and shank portion incorporating a reinforcing fillet and constituting a fatigue area where breakage sometimes occur in the parts. Furthermore, in the event that the shank portion of the piercing punch becomes excessively worn after continued sharpening the entire punch must be discarded and accordingly the high-test machine steel of the body portion of the punch must also be discarded.

The primary object of invention is to overcome the shortcomings of the prior art providing a novel piercing punch assembly which includes an elongated substantially uniform cross sectioned piercing punch which is constructed separately from a sleeve member wherein the sleeve member may be made of a relatively low grade steel and may be salvaged for use with other piercing punches.

A further object of invention in conformance with that set forth is to provide a novel piercing punch assembly incorporating mounting means which permit an adjustment for length in the event the lower portion of the piercing punch becomes worn thereby permitting the piercing punch to have a longer life and be useable for plural punching operations.

Another object of invention in conformance with that set forth is to provide a novel piercing punch assembly which includes a replaceable punch member having a uniform outside diameter permitting ready heat treating of the same as well as affording a piercing punch which may be ground on centerless grinding apparatus.

Another object of invention in conformance with that set forth is to provide in a piercing punch assembly of the character set forth mounting washer means which may be reversed in a retaining recess on a punch pad which accommodates the novel piercing punch assembly whereby means are afforded for providing an additional usable length available during punching operations.

A still further object of invention in conformance with that set forth is to provide a novel punch assembly of the character set forth which may be replaced by a punch including a pilot nose affording means for orienting a workpiece for future punching operations with respect to a previously formed punch hole.

And yet another object of invention in conformance with that set forth is to provide a novel piercing punch assembly which is readily and economically manufactured, easily used, and highly practical, serviceable and utilitarian for the purpose intended.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accomwith I Patented Oct. 1, 1957 panying drawings forming a part hereof, wherein like numerals refer to like parts throughout and in which:

Figure l is a vertical sectional view of the novel piercing punch assembly, showing the relative position thereof with respect to the conventional punch press parts;

Figure 2 is a view similar to Figure 1 showing an alternate position of the parts of the novel piercing punch assembly;

Figure 3 is an exploded perspective view of the novel piercing punch assembly with the parts thereof disassembled; 1

Figure 4 is a perspective view of a pilot member to be substituted for the punch member of the novel piercing punch assembly; and

Figure 5 is a fragmentary vertical sectional view on a reduced scale, showing an alternate manner of resiliently supporting the pilot member.

Referring to the drawings in detail, fragmentary die set portions of a conventional punch press assembly are indicated at 10 and 12, said punch press assembly including a punch pad 14, a stripper member 16, and a die block 18. The upper die set portion 10 will include a recess bore portion 28 in longitudinal alignment with a conventional guide bushing 22 suitably secured in the stripper member 16, and the die block 18 will have secured therein in longitudinal alignment with the bore 20 and the guide bushing 22, an insert die 24 which is in alignment with a longitudinally disposed bore portion 26 extending through the die set portion 12. The insert die 24 includes a lower downwardly opening conical bore portion 28 permitting the ready passage therethrough of a punch slug which will be struck from the stock being punched which is indicated by the phantom lines at 30 in Figure 1. The ptmch pad 14 includes a transverse bore portion 32 which is in communication with an enlarged diameter recess portion 34 which extends through the upper surface portion 36-of the punch pad in communication with the bore 20 previously mentioned. Removably supported in the bore portion 32 and recess 34 of the punch pad 14 is a removable piercing punch assembly indicated generally at 38. The piercing punch assembly 38 includes an elongated rod-like punch member 40 which has a substantially uniform outside diameter, a tubular support sleeve 42, and a mounting washer member 44.

The punch member 40 is made from a suitable hightest or high-speed machine steel having a lower sharpened or punching end 46 which is extendible through the guide bushing of the stripper and the die insert of the die block in the conventional manner. The punch member 40 has extending into the outer peripheral upper end portion 48 thereof an annular groove 50 defining a reduced diameter longitudinally extending mounting pin portion 52 for facilitating the mounting of the punch member in the mounting washer 44 as subsequently will become apparent. Although the punch member 40 has been disclosed as having a circular cross section, it is to be understood that other cross sections, rectangular, diamond shaped, etc., may be utilized, and as will become aparent, although an annular groove 50 has been indicated in the upper intermediate peripheral portion of the punch member, the mounting pin means could comprise a pair of oppositely-disposed intermediate notches in said punch member which will accordingly define an intermediate key portion to cooperate with the mounting washer in the identical manner in which the annular groove and mounting pin cooperate with the mounting washer.

Inasmuch as the punch member 40 has a substantially uniform cross section or outside diameter, such construction lends itself to eificient heat-treating processes wherein substantially all of the punch member will receive a uniform degree of temper.

Furthermore, when the punch this type punch member lends itself to ready grinding on centerless grinders which eliminates the necessity for having formed on the ends of the punch member bore p t- 11 fa i t t n the o n of the punch mi mber on centers of a grinding machine.

The sleeve member 42 is of a substantially shorter length than the punch member 4!) and has an outside diameter similar to the bore 32 through the punch pad wherein said sleeve member 42 is mounted in the bore 2 f th P n PM b me of a P e t- F r h rmore, the sleeve member 42 is constructed of a relatively low grade steel and can be heat treated separately from the punch member 49 thus facilitating an economy the manufacture of the assembly. In addition, the sleeve mem r a e usabl wit ethe Pun h be of a given punch set and thus may be salvaged. The sleeve member 42 has a longitudinally extending-bore portion 54 t ro whi h he pun memb r 4 e h mounting washer 44 has an outer configuration conforming to the recess 34 in the punch pad 14. Although shown to be circular, the mounting washer 44 may assume any desirable external configuration. The mounting washer 44 includes opposite sides 56 and 58 each of which is capable of being engageable with the upper end portion 60 of the sleeve member 42, said washer member having extending into the side 56 a laterally or radially extending slot portion 62 which will bedisposed in intersecting relationship relative to the bore 54 of the sleeve 42 when the mounting washer 44 is in position in the recess 34 of the punch pad. The slot 62 in the mounting Washer defines a thinned-out section 66 in the mounting washer adjacent the side 58 thereof and extending through the thinned-out section 66 an undercut is laterally extending slot portion 63 which defines a pair of oppositely disposed and substantially parallel flanges 70 and 72 which receive therebetween the'rnounting pin portion 52 of the punch member 40. i

The mounting washer 44, if desired, may include in h Fl S 5 54 5 .5 @91 1? recss Po t 7 41 6 respectively, conforming to the outside dimension or configuration of the sleeve member 42 and receiving the upper end oil of the' sleeve member therein depending upon which side of the mounting washer is disposed adjacent the end of the sleeve-member. i H l The novel piercing punch assembly is used as follows:

h sl v nemhe 'f l i l i el el in th i ch'tiad the parts of the punch press previously having been aligned, after which the punch rnember 40 is inse rted laterally into the lateral slot portion of the niounting washer 44 where af ter the mounting washer "44 and the punch member 40am inserted into one pr the positions shown Figures 1 and 2. In Figure 2, will be noted th t e r a is d 2 thin edu h h 9 the ht n washer ,44 is disposed in spaced relationship with the upper end ,60 of the mounting sleeve; thus afiording a relatively shorter length punch member to-be availible for a given .punch operation: R Ih the even t that thecutting edge or lower end 4 6 of the punch member 40 becomes a asale ha t be Sh r he it sh th P h member is not of a sufficient length for a given punching operationjthe punch member mounting washer maybe rierrioyed frorn'jhe pad whereafter the mounting washer be reversed or disposed in the position shown in Figure 1 thus making available an additional punch i ng length for given operation. As is readily apparent, inthe event the punchmember 40 has to be discardeddue to damage, etc, another similar punch mbe m y h subs t t e o- I As seen {in Figure 2, the bore portion of die set portion 10 will receive the upper end 48 of the punch member .40 when the. assembly, is ;used in the manner disclosed in Figure 2 A e wh st e-f t s is fl asl ss Pilqt 99 m m d c e e heral a 7 w ishhel d u-ah .9 sated bo y member 13;" fi mi a W MP??? mashe -49 said body member including the annular groove portion 82 and mounting pin 84 similar to portions 50 and 52 of the punch member 40, the lower end of the body member 80 being tapered at 86, it being understood that the pilot punch member of Figure 4 will be aligned in a previously punched hole in the stock whereafter subsequent holes to be punched will be properly oriented with respect to one of the novel punch assemblies shown. The grooue portion 82 forming the mounting pin 84 on the pilot punch will facilitate the mounting of the pilot punch in the same manner as described with respect to the piercing punch of Figures 1 through 3.

Shown in Figure 5 on a reduced scale are fragmentary portions of a die set portion 3,6 and punch pad 14. The die set portion includes a recess bore portion 90 in longitudinal alignment with the transverse bore portion 32 which terminates in an enlarged diameter recess portion 34 extending through the upper surface portion of the punch pad 14, the'recess'p ortion being of a larger diameter than the recess portion 34; A pilot punch member is indicated generally at 73 including a body portion 80 having an afqmular' groove portion 82 and a mounting pin 84 similar to that of'Figure 4. The pilot punch member will befmounted on a mounting washer 44 as is the I i i e ber and pilot punch body member 80. interposed between an upwardly disposed side 56'or 58 qfthe Iwash'er member 44 is one end of a compression 7 spring element 9 2, the other end of which being engaged If wall ortion 94 of the recess bore portion 90. Thus limited t t wQzud movement er the pilot punch memh is 'nerii itt Jo a s dam t e p l t p n member in the event the previously punched hole in the stock 30 is not properly aligned with the pilot punch nieiuher.

Thus there has been disclosed a novel piercing punch assembly which fully conforms with the' objects of invention heretofore set forth. i

'Various positional directional terms such as fouterfi' lower, etc., are utilized herein and have only'a relative connotation to aidin describing the device and it is not intended to require any particular orientation with respect to any external elements. 7 i

v The foregoing gis' 'considered as illustrative only of the principles of the invention. Further, since numerous modiiications and changes will readilyloccur to those skilled in heart, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of' the appended claims.

What is claimed as new is as follows:

1. A piercing punch assembly comprising an elongated punch member of high-speed steel, said punch member having a substantially uniform outside diameter, said punch member including a longitudinally extending reduced dimension mounting pin portion adjacent one end porti on thereofja' tubular sleeve member having a longitudinal bore portion through which the punch member 'is removably received, said sleeve member being of a shorter length than the punch membef and being removably received in atransver'sebore portionof a punch pad, and a mounting washerm ember .removably received in a conforming recess of the punch pad in alignment with the transverse bore portion therein, said mounting washerincluding oppositelside portions engageable with an upper end portion of the s leeve member, one surface portion of thewasher member including a thinned-out section having a lateral .slot portion extending through one edge of the washer element-forinterseciting relationship with the longitudinal bore of said sleeve member, ,said slot portion including an undercut portiondefining a pair of parallel flanges for removablyreceiving the mounting pin portion of the punch mernber therein.

2. ,A .piercing jpunch assembly comprising an elongated punch member of high-speed tool steel, said punch ,mem-

her having a substantially uniform circular cross section, an annular groove portion extending about said punch member defining a longitudinally extending mounting pin portion on said punch member adjacent one end thereof, a sleeve member having a longitudinally extending bore portion therethrough for removably receiving the punch member therein, said sleeve member being of a shorter length than the punch member and being removably received in a transverse bore portion of a punch pad, and a mounting washer member removably received in a conforming recess in the punch pad in alignment with the transverse bore portion thereof, said mounting washer having opposite side portions engageable with an upper end portion of the sleeve member, one side portion of the washer element having a thinned-out section having a lateral slot portion extending through one edge portion of the washer member for intersecting relationship with the bore portion of the sleeve member, said slot portion including an undercut portion defining a pair of parallel slots removably receiving therein the annular groove portion of the punch member.

3. A piercing punch assembly comprising an elongated punch member of high-speed steel, said punch member having a substantially uniform outside diameter, said punch member including a longitudinally extending reduced dimension mounting pin portion adjacent one end portion thereof, a tubular sleeve member having a longitudinal bore portion through which the punch member is removably received, said sleeve member being of a shorter length than the punch member and being removably received in a transverse bore portion of a punch pad, and a mounting washer member removably received in a conforming recess of the punch pad in alignment with the transverse bore portion therein, said mounting washer including opposite side portions engageable with an upper end portion of the sleeve member, one surface portion of the washer member including a thinned-out section having a lateral slot portion extending through one edge of the washer element for intersecting relationship with the longitudinal bore of said sleeve member, said slot portion including an undercut portion defining a pair of parallel flanges for removably receiving the mounting pin portion of the punch member therein, the washer member including oppositely disposed recesses extending into the opposite side portions thereof and conforming to the outer periphery of the sleeve member and removably receiving the upper end portion of the sleeve member therein.

ONeill Sept. 11, 1888 Taylor Dec. 12, 1899 

